1. Field of the Invention
The present invention relates to a semiconductor photoelectric conversion device which has at least one PIN structure in which a first conductivity type (P- or N-type) non-single-crystal semiconductor layer, an I-type non-single-crystal semiconductor layer, and a second conductivity type (opposite from the first conductivity type) non-single-crystal semiconductor layer are sequentially laminated in that order. Further, the present invention pertains to a method for the manufacture of such a semiconductor photoelectric conversion device.
2. Description of the Prior Art
Heretofore a variety of semiconductor photoelectric conversion devices have been proposed which are of the type having at least one PIN structure mentioned above.
With this kind of devices, light incident thereto creates carriers, that is, electron-hole pairs in the I-type layer and the electrons and holes flow into one of the first and second conductivity type layers, that is, the N-type layer, and into the other, that is, the P-type layer, respectively, developing photovoltage. Accordingly, in order to obtain a high photoelectric conversion efficiency, it is desired that the I-type layer of the PIN structure have no recombination centers with which the carriers combine. To this end, it is the general practice in the prior art to dope the I-type layer of the PIN structure with hydrogen or a halogen as a recombination center neutralizer.
Nevertheless, a relatively large number of recombination centers remain unextinguished in the vicinities of the boundaries between the I-type layer and the P-type layer and between the I-type layer and the N-type layer. These remaining recombination centers cause losses of the electrons and holes flowing toward the N-type and P-type layers, respectively. Therefore, the prior art devices have the defect of low photoelectric conversion efficiency although the I-type layer of the PIN structure is doped with the recombination center neutralizer.